How to knock the corners off an image?

[johnw436]

I've pulled all of my hair out. I've searched the archives. I need

help!

 

I have been working on a project for a church in which the goal is

to photograph all of the stained glass windows. My end goal is to

make individual prints of the windows as well as making a poster

with all of the windows, icons, murals, etc arranged nicely.

 

I am working from scans of the negatives. I am all but done with

edits to the individual windows. (I am a total newbie in PS. I am

using CS2 and learning as I go. Perspective correction was a real

fun time, let me tell you.)

 

 

Here's my dilemma. The stained glass windows are typical in that

the tops are arched. My photos are rectangular. I want to knock

the corners off and be left with the window itself. That way I can

arrange/print them on a background of any color without each window

having two big black corners at the top.

 

I've been trying magnetic lasso. Works fairly well. My problem

after cutting the selection off is that I'm left with a big white

corner with a frame around it. I don't want the frame. I can't

tell if it's simply PS's way of showing me where the paperspace is

or if it's telling me I can't make rounded-top photos.

 

I admit my ignorance on this. Please help. I'm beyond ridicule at

this point, so have your way with me...

[james_bass1]

First, I recommend going to www.lynda.com and taking the course Enhancing Digital Photography. It will cost you $25 for a one month subscription to the site, and you'll learn by watching Quicktime movie demonstrations. I've been using PS since version 2.0 and found much to learn.

 

Now, for your question. Masking with a paintbrush is easier than the lasso if you want a graduated edge. But I wouldn't even do that. I'd probably play with an adjustment layer that was masked, but with a hole punched out. This will be meaningless to you until you get a little more grounded in PS. Do so, because the time you spend learning will save you much time in the long run.

 

Plus, you'll have more fun!

[mark pav]

If you're working on the basic background layer then whenever you erase part of your

picture (in any way) then the background colour shown in your colour picker will come

through the gap. Does that make sense?

 

The way to avoid this is to work on a duplicate layer of the background. Copy thr

background layer and then delete it, so you only have the copy left. If you work on that

then what will show through the erased bits of your pic will be the grey checkerboard

pattern Photoshop sets as a default for where there's no image. Of course, if you print the

pic like that, you'll still get a white background on the printed version.

 

Hers'a visual example:<div></div>

[twmeyer]

Happy New Year. <p>Create a new layer and in the drop down box in the layers palette where it says "normal" change that to "difference" The image goes black. Slide the "opacity" to something that lets you see the image. Add an auto mask to the layer by clicking on the little camera looking thing at the bottom of the layers palete. Select the "Paintbrush tool" and click on the little black and white squares that set your foreground/background colors to white and black. Use black to paint the layer away, and use to white to bring it back (be sure the auto mask is selected in the layers palette). Use the brush "opacity" and "flow" sliders (top right) and the brush diameter (brush palette: diameter and hardness) to vary the intensity and size of the effect. You can then use the layer opacity to raise and lower the effect you create over the whole image. <p>The nice thing about this technique, is that is is completely reversible, regardless of your history settings. You can save it as a photoshop file (PSD) with layers, and work on it for days...weeks...years, and it's still completely reversible... t

[johnw436]

Thank you all so much. Yes, I will take that PS course. I didn't know where to look for such a thing, so the suggestion is much appreciated.

 

Thanks to everyone for the kind suggestions. I will try all of them. As I am finding with PS, there are a lot of ways to do anything. The problem is that none of them are very intuitive if you don't already have a basic grasp of PS. Then again, I guess if it was easy to do you wouldn't need PS...

[twmeyer]

I can recommend the www.software-cinema.com DVDs. You can follow their lessons while simultaneously going through the same steps on your own image (just pause/resume the DVD). There is no time limit on them, and they are much more affordable than most seminars... t